PROJECT ABSTRACT Enrollment and retention are critical components of the effectiveness of HIV- prevention interventions in real-world conditions and have established psychological determinants (Albarracn, Durantini, et al., in press; Noguchi et al., 2007). Without enrollment, HIV-prevention interventions simply cannot have a public health impact (Albarracn, Durantini, et al., in press; Noguchi et al., 2007). Without retention, efficacious multi-session interventions to reduce HIV risk cannot be implemented with either fidelity or effectiveness. Currently, interventions that are tested under conditions similar to the ones that are likely during actual implementation show relatively low retention (Noguchi et al., 2007), even though retention strongly predicts behavior change. More importantly, no psychological methods to increase retention have been evaluated before. This application for renewal of R01 NR08325 requests five years of funding to test two innovative communication methods to increase retention, defined as return to the sessions of a one-on-one multi-session HIV-prevention-counseling program. These methods are based on a social psychological model of selective exposure in which retention is a function of motives to achieve self-validation (i.e., empowering) and objective outcomes (i.e., emotional/social and instrumental support beyond HIV prevention). In the proposed study, 656 clients from STI (sexual-transmitted- infection) clinics in Duval County (Florida) will be recruited and randomly assigned to one four study arms. At the end of the counseling first session, participants will receive a videotaped message that either does or does not contain a video to empower clients to take control of their behavior change by returning to the next session (self-validation message), and that either does or does not describe the counseling sessions as a source of emotional/social support for clients, as well as information about, detection of, and referral for health problems in addition to HIV (e.g., related to cardiovascular health). Altogether, the design is a 2-way factorial with four cells. The outcome of the study will be measured by the mean number of completed sessions after the presentation of the video. Based on our past success with this line of research, the proposed project can be expected to provide tools to maximize intervention effectiveness and to illuminate the psychological pathways leading to intervention retention. For example, these innovative messages may be used to increase retention during the implementation of the available arsenal of outstanding efficacious interventions to reduce HIV, STIs, and the consequences of HIV and STIs (e.g., cancer, diseases of the central nervous system). The Florida populations that are directly implicated have alarming HIV prevalence and incidence, both of which may decrease with improved retention in HIV-prevention interventions. In addition, the public health impact of the project is likely to extend to other affected areas in the United States and the world.